System Design And Verification Of Measuring Radiant Physical Properties Of Solid Particle And Liquid At High Pressure And Temperature

Radiant physical properties of liquid and solid particle are not only the important parameters of design for thermal energy conversion device, such as the aerospace engine and coal-fired boiler, but also important basic data in the process of practice activities of remote sensing imaging, water quality monitoring, solar thermal chemical reaction and so on. The accuracy of their radiation physical properties has a great influence on many fields. The classical simulation mode l of optical constant still cannot make a reasonable prediction about optical constants of liquid at high temperatures and pressures. But the experimental measurement result is more reliable, so it play a reference and guiding role for simulation calculati on. However, system design for measuring radiant physical properties of solid particle and liquid at high pressure and temperature is relatively rare.This thesis carried out the research design work about system for measuring radiant physical properties of solid particle and liquid at high pressure and temperature. The new system can work in two modes: solid particles or liquid measurements. the system can realize control of temperature from room temperature to 200℃ and pressure from atmospheric pressure to 0.5MPa.In the aspect of system design and optimization, first of all, after the analysis of deficiency of common sample cell, a simulation analysis has been made on the sample cell for improving its structure. Considering the influence of the optical window thickness on the transmissivity and mechanical properties, 2mm thickness of the optical window has been selected. Secondly, the information acquisition control system were designed by using a pressure transmitter and a temperature acquisition module. It can acquire real-time working condition, and use PID algorithm to realize automatic control of system temperature and pressure, providing constant temperature and constant pressure environmen t. Finally, measuring system has been constituted in a platform of elliptic polarization spectrometer. The result shows that the system temperature and pressure stability is good. The temperature deviation is less than 0.1 ℃, meanwhile the pressure deviation is less than 1.7k Pa. Maximum temperature difference of sample cell is 8℃, so temperature uniformity is good. It takes 40 minutes that system pressure drop is 15 k Pa, which system liquid tightness is satisfactory.In the aspect of system feasibility verification and experimental measurements, first, measuring the total transmission of distilled water and organic ethanol at room temperature and atmosphere pressure, absorption index has been obtained by the use of double optical distance inversion algorithm, and were compared with the literature, which proved the verification feasibility of this system. Secondly, the influence of temperature and pressure on radiation physical properties of ethanol and rapeseed oil. The results showed that a large effect of temperature on the physical properties of ethanol, relative to 20℃, the biggest change rate of radiation physical properties at 50℃ and 80℃ is 17.1% and 50.3%.But the effect of pressure is little, and relative to 0.1MPa, maximum change rate at 0.3MPa and 0.5MPa 2.07% and 7.44% respectively. Radiation properties of the rapeseed oil changes significantly at different temperature, and relative to 20℃,the maximum change rate at 60℃ and 100℃ is 21.6% and 59.9% respectively. Finally, the optical constants of Si O2 optical windows and four catalysts in solar thermochemical have been measured. Temperature dependence of the optical constants of Si O2 optical window within 200℃ is little, so it has stable optical performance. The complex refractive index of the solid particles is higher, which make them strongly absorb infrared wave energy and change the incident light path to enhance the heat absorption and improve reaction speed inside the reactor.